MPEG Tutorial A Guide to MPEG Fundamentals and Protocol Analysis (Including DVB and ATSC) A Guide to MPEG Fundamentals and Protocol Analysis Primer Section 1 – Introduction to MPEG ..............................................................................1 1.1 Convergence ............................................................................................................................................1 1.2 Why Compression Is Needed ....................................................................................................................1 1.3 Principles of Compression..........................................................................................................................1 1.4 Compression in Television Applications ....................................................................................................2 1.5 Introduction to Digital Video Compression ................................................................................................3 1.6 Introduction to Audio Compression ..........................................................................................................5 1.7 MPEG Streams..........................................................................................................................................6 1.8 Need for Monitoring and Analysis ..............................................................................................................7 1.9 Pitfalls of Compression ..............................................................................................................................7 Section 2 – Compression in Video ............................................................................8 2.1 Spatial or Temporal Coding? ....................................................................................................................8 2.2 Spatial Coding ..........................................................................................................................................8 2.3 Weighting ................................................................................................................................................10 2.4 Scanning ..................................................................................................................................................11 2.5 Entropy Coding ........................................................................................................................................11 2.6 A Spatial Coder ........................................................................................................................................12 2.7 Temporal Coding......................................................................................................................................13 2.8 Motion Compensation ..............................................................................................................................14 2.9 Bidirectional Coding ................................................................................................................................16 2.10 I-, P- and B-pictures ................................................................................................................................16 2.11 An MPEG Compressor ............................................................................................................................18 2.12 Preprocessing..........................................................................................................................................21 2.13 Wavelets ................................................................................................................................................22 Section 3 – Audio Compression ..............................................................................23 3.1 The Hearing Mechanism..........................................................................................................................23 3.2 Subband Coding......................................................................................................................................24 3.3 MPEG Layer 1..........................................................................................................................................25 3.4 MPEG Layer 2 ........................................................................................................................................26 3.5 Transform Coding....................................................................................................................................26 3.6 MPEG Layer 3 ........................................................................................................................................27 3.7 MPEG-2 Audio ........................................................................................................................................27 3.8 MPEG-4 Audio ........................................................................................................................................27 3.9 AC-3 ......................................................................................................................................................28 Section 4 – The MPEG Standards ..........................................................................29 4.1 What is MPEG ........................................................................................................................................29 4.2 MPEG-1 ..................................................................................................................................................29 4.3 MPEG-2 ..................................................................................................................................................30 4.3.1 Profiles and Levels in MPEG-2 ................................................................................................................30 4.4 MPEG-4 ..................................................................................................................................................32 4.4.1 MPEG-4 Standards Documents ..............................................................................................................32 4.4.2 Object Coding ........................................................................................................................................32 4.4.3 Video and Audio Coding ..........................................................................................................................34 4.4.4 Scalability ................................................................................................................................................35 4.4.5 Other Aspects of MPEG-4 ......................................................................................................................36 4.4.6 The Future of MPEG-4 ............................................................................................................................37 4.5 MPEG-7 ..................................................................................................................................................38 4.6 MPEG-21 ................................................................................................................................................39 www.tektronix.com/video_audio i A Guide to MPEG Fundamentals and Protocol Analysis Primer Section 5 – Elementary Streams ............................................................................40 5.1 Video Elementary Stream Syntax ............................................................................................................40 5.2 Audio Elementary Streams ......................................................................................................................41 Section 6 – Packetized Elementary Streams (PES) ..............................................42 6.1 PES Packets............................................................................................................................................42 6.2 Time Stamps ..........................................................................................................................................42 6.3 PTS/DTS ..................................................................................................................................................42 Section 7 – Program Streams ................................................................................44 7.1 Recording vs. Transmission ....................................................................................................................44 7.2 Introduction to Program Streams ............................................................................................................44 Section 8 – Transport Streams ..............................................................................45 8.1 The Job of a Transport Stream ................................................................................................................45 8.2 Packets ..................................................................................................................................................46 8.3 Program Clock Reference (PCR) ............................................................................................................46 8.4 Packet Identification (PID)........................................................................................................................47